Silicon-Modified Nickel Oxide Cathode for Battery Durability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Lithium nickel complex oxide-based nonaqueous electrolyte secondary batteries face durability issues due to voids within the positive electrode active material, which affect contact area and overall battery performance.

Innovation Solution

Incorporating silicon into the positive electrode active material with nickel-excess lithium nickel complex oxide, forming secondary particles with a layered rock-salt structure and low porosity to enhance durability by reducing internal voids and stress during charging/discharging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If lithium nickel complex oxide with high nickel content is used as positive electrode active material, then capacity and cost are improved, but durability is worsened

Engineering Contradiction:

ImprovecapacityVSAvoiddurability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by creating a core-shell structure where the inner core contains nickel-excess lithium nickel complex oxide for high capacity, while the outer shell contains lithium cobalt complex oxide for durability. This spatial differentiation of material properties allows the high-nickel core to provide capacity while the protective cobalt-rich shell maintains structural stability and durability during charge-discharge cycles.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining lithium nickel complex oxide and lithium cobalt complex oxide into a single positive electrode active material system. The composite structure leverages the high capacity advantage of nickel-based materials while incorporating the durability benefits of cobalt-based materials, achieving a synergistic effect that resolves the durability-capacity trade-off.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If conventional manufacturing methods are used for positive electrode active material, then manufacturing process is simple, but porosity is high leading to reduced durability

Engineering Contradiction:

Improvemanufacturing process simplicityVSAvoiddurability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the porosity of the positive electrode active material to be 0% or less, and controlling the particle size distribution and morphology during manufacturing. By adjusting these physical parameters during the manufacturing process, the patent achieves low porosity that eliminates internal voids and improves durability, while still maintaining a feasible manufacturing approach using conventional sintering and processing techniques.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10916768B2Positive electrode active material for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery

Publication Date: 2021.02.09 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

A positive electrode active material for a nonaqueous electrolyte secondary battery contains silicon and lithium nickel complex oxide having a layered rock-salt structure and is composed of secondary particles formed of aggregated primary particles. Lithium nickel complex oxide contains 80 mol % or more of nickel, based on the total amount of metal excluding lithium, silicon content is 0.6 mass % or less based on the total amount of the positive electrode active material, and a porosity of the positive electrode active material is 0% or more and 1% or less.